The term "hardcopy output device" includes a variety of printers and plotters, including those using thermal inkjet and electrophotographic technologies to apply an image to a hardcopy medium, such as paper, transparencies, foils, and the like.
Most earlier hardcopy print devices have parameters that balance the competing requirements of throughput, typically measured in pages per minute, and the print quality of the hardcopy output. These parameters also control the rendering of the document into both the graphics format and hardware configuration of the particular device. However, the optimum settings for these parameters often varies for different types of documents. For example, documents with only black ink text have a different set of optimum parameters than documents with colored images or business graphics.
Most hardcopy print devices have a variety of mechanical print modes and rendering or halftoning options that affect the throughput and output quality. This is especially true for current color printers based on inkjet technology. These modes are often under the user's direct control, or they are set to default values calculated to provide only adequate quality output and throughput for the overall image. In this default mode, the earlier devices typically had parameters selected to optimize the most typical type of document they produced, while delivering only acceptable results when printing other types of documents.
When under user control, in theory, the operator optimizes the printing parameters through trial and error. While an experienced operator may eventually determine the relationships between each printing parameter and its effects on the various types of outputs, this rarely happens. Most operators never master an understanding of the complex relationship between the numerous controllable printing parameters and the quality of the output. Indeed, only experts experienced in the rendering and printing technology of a particular hardcopy device have a good chance of selecting the optimum printing parameters, but this task is quite labor intensive.
Moreover, in the vast majority of earlier color matching techniques, it was impossible to vary the print mode settings on a page by page basis, or for different elements on a single page. Thus, the physical capabilities of hardcopy print devices are rarely exercised by the vast majority of operators. As a result, often the printed output is of far lower quality, and with less throughput, then could have been achieved under optimal operating conditions.
For example, consider a sheet containing text, a business chart, and a photographic image. When color matching was optimized for the photograph, the business chart suffered a loss of vivid color graphics. If instead, the color settings for the page were adjusted to deliver a brighter, more saturated graphic, then the photographic image lost its lifelike appearance. Thus, for the main stream operator using the earlier hardcopy devices, optimal hardcopy results were rarely if ever achieved.